Product carrier for environmental test system

ABSTRACT

Disclosed is an environmental test apparatus having a thermal chamber for stress testing electronic products. The apparatus has a carrier for supporting the products in the chamber and equipment for monitoring product characteristics during stress testing. The improved apparatus has an auxiliary chamber in which ambient temperature and humidity conditions prevail. A flexible partition is interposed between the thermal and auxiliary chambers, the monitoring equipment is in the auxiliary chamber and the carrier having products under test mounted thereon is in the thermal chamber. A conveying mechanism is in the auxiliary chamber and the support platform is in driven engagement with such mechanism, thereby causing movement of the platform along the auxiliary chamber.

RELATED APPLICATION

This application is a division of application Ser. No. 08/841,216, filedApr. 30, 1997, now U.S. Pat. No. 6,005, 404.

FIELD OF THE INVENTION

This invention relates generally to electrical measuring and testingand, more particularly, to product measuring and testing involvingtemperature cycling.

BACKGROUND OF THE INVENTION

Environmental test chambers are widely used to test electrical productssuch as printed circuit boards and other electrical/electronic productswhich include a printed circuit board as a component part. Such testinginvolves monitoring certain electrical operating characteristics of theproduct while it is undergoing extreme changes in temperature.Temperature cycling over a range of +125° C. to −65° C. (about +255° F.to −85° F.) is not uncommon and is often accompanied by extreme changesin humidity and/or by vibrating the product under test. In the industry,testing of this type is often referred to as “stress testing.”

A primary reason that product stress testing is undertaken is toidentify particular products (within a larger group of products) whichexhibit characteristics evidencing probable premature failure. And suchtesting is intended to cull out those products which actually failduring test. In the vernacular of the industry, such products are saidto exhibit “infant mortality.” Those products which do not exhibitinfant mortality are much more reliable in the automotive, aircraft,military or other application in which they are used. U.S. Pat. No.3,656,058 (Leathers); U.S. Pat. No. 4,683,424 (Cutright et al.); U.S.Pat. No. 4,949,031 (Szasz et al.) and U.S. Pat. No. 5,021,732 (Fuoco etal.) all disclose apparatus used for environmental stress testing.

Designers of environmental test chambers must deal with a number ofengineering considerations. One is the rapidity with which thetemperature in the product-containing chamber can be changed. In a testchamber having refrigeration and heating systems of a particular size,the rate at which the temperature can be changed is, in significantpart, a function of the mass (e.g., the mass of the products and productcarriers) in the chamber. This is so because the heat absorbed by thechamber contents and the heat which must be removed therefrom is afunction of such mass.

A household refrigerator is a good analogy of the foregoing. For aparticular refrigerator, two pounds of foodstuffs in the refrigeratorare more quickly cooled to a particular temperature than twenty poundsof foodstuffs. And as a corollary, cooling twenty pounds of foodstuffsto a particular temperature within a stated time requires a largerrefrigeration unit than is required to cool two pounds of foodstuffs tothe same temperature within the same time.

Another engineering consideration involves the equipment used to monitorthe electrical operating characteristics of the products under test.Such equipment is temperature sensitive and must be maintained nominallyat room ambient conditions. In other words, such equipment should not bein the chamber with the products undergoing test.

Still another engineering consideration is whether to configure the testchamber for batch-process or continuous- process testing. The apparatusof above-noted Szasz et al. patent is for batch testing in that a numberof products are placed on a pallet which is inserted into the chamber.All the products on the pallet undergo test simultaneously and aftersuch test is completed, the pallet and its “batch” of products isremoved and another pallet loaded with products to be tested isinserted.

On the other hand, the vibration chamber disclosed in U.S. Pat. No.5,226,326 (Polen et al.) may be referred to as a type of continuoustesting arrangement. Such chamber uses a conveyor having spaced pairs ofrollers to grasp respective edges of flatwise-oriented printed circuitboards to be tested. Similarly, U.S. Pat. No. 5,397,998 (Soeno et al.)discloses several different arrangements of a conveyor and products tobe tested carried atop such conveyor. In one arrangement, feederapparatus along the conveyor supply electric power to the productsduring burn-in and the “burned-in” product are then tested after exitingat the end of the conveyor.

While these earlier arrangements are thought to have been generallysatisfactory for their intended uses, they are not without disadvantagesfor some types of applications. For example, the conveying arrangementsshown in the Soeno et al. patent apparently do not permit instrumentedproduct testing while the product is moving through the chamber. Inother words, such instrumented testing is carried out after the productleaves the burnin chamber. The “failure mode” characteristics exhibitedby the products while in the burn-in chamber and after they leave suchchamber may differ markedly.

Yet another disadvantage of the conveying arrangements of the Soeno etal. patent is that the mass of the conveyor (as well as that of theproduct to be tested) is in the burn-in chamber. Chamber temperaturechanges can be accomplished and maintained only by adding heat to orremoving heat from the conveyor components.

Still another disadvantage of prior art arrangements is that theyseemingly have not appreciated how to configure test chambers so thatthe size and capacity thereof can be selected or changed to suit aparticular application. For example, the arrangement shown in FIG. 5 ofthe Polen et al. apparently has a fixed length which cannot be changed.At least, there is no suggestion to the contrary.

A new environmental test apparatus which addresses certain shortcomingsof earlier apparatus would be an important advance in the art.

OBJECTS OF THE INVENTION

It is an object of the invention to provide an environmental testapparatus which overcomes certain problems and shortcomings of the priorart.

Another object of the invention is to provide an environmental testapparatus which is useful for stress testing electrical and electronicproducts.

Another object of the invention is to provide an environmental testapparatus which permits simultaneous product electrical testing andtemperature stress testing.

Still another object of the invention is to provide an environmentaltest apparatus which minimizes the mass contained in the thermalchamber.

Another object of the invention is to provide an environmental testapparatus which implements continuous process testing.

Another object of the invention is to provide an environmental testapparatus by which continuous process testing may be carried out whilemaintaining the test instrumentation substantially at room ambientconditions.

Yet another object of the invention is to provide an environmental testapparatus which may be “custom-configured” for any one of a variety ofapplications. How these and other objects are accomplished will becomeapparent from the following descriptions and from the drawings.

SUMMARY OF THE INVENTION

The invention involves an environmental test apparatus of the typehaving a thermal chamber for stress testing electronic products. Suchapparatus includes a carrier for supporting the products in the chamberand instrument-type test equipment for monitoring productcharacteristics during stress testing.

The improved apparatus has an auxiliary chamber and a flexible partitioninterposed between the thermal and auxiliary chambers. The carrier is inthe thermal chamber (where the temperature environment is madeintentionally harsh) and the test equipment is in the auxiliary chamberwhich is nominally at room ambient temperature and humidity. A highlypreferred embodiment of the carrier includes a flat, sheet-like productsuch as a feedthrough card having attached thereto a fixture forreleasably mounting an electronic product, e.g., a printed circuitboard, on the carrier.

The carrier includes first and second opposed, parallel carrier surfacesand the partition includes first and second partition members bearingagainst the first and second carrier surfaces, respectively. A preferredpartition member is a strip-mounted brush with carbon-bearing bristlesfor reducing static electricity. Separate partition members are mountedat either side of the carrier and resiliently bear against a respectivecarrier surface to prevent significant air transfer between thechambers.

It is particularly desirable to prevent warmer, more humid air in theauxiliary chamber from migrating or transferring to the thermal chambersince such transfer speeds the rate at which frost accumulates in thethermal chamber. In a highly preferred apparatus, there are pluralpartitions, one being a primary partition. One (and preferably two)auxiliary partitions are spaced from one another and from the primarypartition and are interposed between the primary partition and theauxiliary chamber.

While the partition members perform acceptably to prevent air transferbetween chambers and, particularly, to prevent such transfer from theauxiliary chamber to the thermal chamber, it is preferred to take yetadditional measures to inhibit air transfer. The spaced-apart partitionsdefine a flow path between them. Dry air is caused to flow along theflow path, thereby substantially preventing moisture from migrating fromthe auxiliary chamber to the thermal chamber.

The new apparatus has yet other features which facilitate movement ofthe carrier along the thermal chamber and which facilitate productmonitoring during temperature stress testing. The apparatus includes asupport platform in the auxiliary chamber. The carrier is attached tothe support platform and extends downwardly through the partition. Anexemplary support platform is a square or rectangular slab made ofDELRIN™ plastic or the like.

A conveying mechanism is also in the auxiliary chamber and the platformis in driven engagement with the conveying mechanism to cause movementof the platform along the auxiliary chamber. A specific conveyingmechanism has two spaced-apart sections, each such section comprising anendless belt supported by rollers and, typically, driven by one roller.The spaced-apart edges of the platform rest on respective conveyingsections.

It is also highly desirable to be able to electrically operate theproducts under stress test as they move along through the apparatus.Thus, the auxiliary chamber contains a power bus embodied as twoparallel, spaced-apart rails. The support platform includes collectorshoes in electrically-conductive relationship to the power bus, therebyproviding power to products mounted on the carrier. In one preferredembodiment, a test board or a board computer is in the auxiliarychamber, is supported by the platform, moves with such platform and iselectrically connected to both the power bus and to the product(s) undertest.

To better accommodate several product carriers with their associatedplatforms, the thermal chamber is horizontally elongate and an airplenum is coextensive with the thermal chamber. The air plenum isisolated from the thermal chamber along most of the length of both butthere are openings at either extreme end of the plenum and thermalchamber so that the plenum is in air flow communication with suchchamber. A motor-driven blower, e.g., a centrifugal blower, urges airalong the plenum and the thermal chamber. A refrigeration evaporator isin the air plenum so that the air being circulated along the plenum andthe thermal chamber may be cooled for stress test purposes.

The new apparatus is thoughtfully configured so that it can be appliedin any one of several application requirements. The apparatus includes aplurality of modules attached to one another. The modules cooperativelyfunction in “building block” fashion in that a portion of the thermalchamber is in each of the modules. Stated in other words, the modulescan be attached to one another end to end to form an apparatus of thedesired length and product testing capacity. The plurality of modulesincludes at least one module having a door mounted for movement betweenan open position for placing products in the thermal chamber and aclosed position for stress testing the products. Typically, a doormodule is placed at either end of the assembly of modules. And,conveniently, each module has levelling feet, thereby permitting themodules to be aligned with one another.

Because the new apparatus has thermal and auxiliary chambers which areisolated from one another and because the auxiliary chamber isessentially always at room ambient temperature, the chambers preferablyhave differing wall configurations. The auxiliary chamber has aplurality of first walls, the thermal chamber has a plurality of secondwalls and each of the second walls is substantially thicker than each ofthe first walls. And each of the second walls includes an insulationlayer making up at least one-half of the wall thickness.

Other details of the new apparatus are set forth in the followingdetailed description and in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative front elevation view of the new testapparatus using plural modules. Separating panels and air flow pathswithin the apparatus are shown in dashed line. Parts are broken away.

FIG. 2 is a top plan view of the apparatus of FIG. 1. Parts are brokenaway.

FIG. 3 is an elevation view of plural modules used in the apparatus ofFIGS. 1 and 2. One module is broken away.

FIG. 4 is a sectional elevation view of a module taken along the viewingaxis VA4 of FIG. 2 or FIG. 3.

FIG. 5 is an elevation view of the product carrier and the productmounted thereon as shown in FIG. 4.

FIG. 6 is an elevation view of a portion of FIG. 4 enlarged to showadditional detail. Parts are broken away.

FIG. 7 is an elevation view of a flexible partition shown in conjunctionwith a feedthrough card of the product carrier.

FIG. 8 is a perspective view of a typical partition member used in thepartition of FIG. 7.

FIG. 9 is a view of a conveyor section used in the apparatus of FIG. 1.Parts are broken away.

FIG. 10 is a top plan view of a portion of the product carrier shown inFIGS. 4, 5 and 6. Such view is along viewing axis VA10 of FIG. 6.

FIG. 11 is a representative elevation view of a door module of theapparatus of FIG. 1. Such elevation view is along viewing axis VA4 ofFIGS. 2 or 3.

FIG. 12 is an elevation view of the door module of FIG. 11 taken alongthe viewing axis VA12 thereof.

FIG. 13 is a representative elevation view of a portion of anotherembodiment of the new test apparatus which incorporates a movable testprobe. Parts are broken away.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Before describing details of the new test apparatus 10, it will behelpful to have an overview description of its general arrangement andoperation. Referring first to FIGS. 1, 2 and 3, an exemplary embodimentof the new environmental test apparatus 10 has first and second sections11 and 13, respectively. The first section 11 has several modules 15coupled to one another and the section 11 is terminated by an entry doormodule 17 at one end and by an exit door module 19 at the other end.

It is to be appreciated that either section 11, 13 may be used alone toconduct only cold stress testing or only hot stress testing,respectively. When a section 11 is used as an apparatus 10 for coldstress testing only, it is highly preferred to configure the exit doormodule 19 to have two spaced-apart doors 21. In that way, the doors 21can be operated sequentially to provide what might be described as anair lock. (It will be apparent from the specification that the doors 21may be used to remove products from the section 11 and that theright-hand door 21 may be used to place products into section 13.)

Each of the modules 15 has an access door 23 for convenient entry intothe thermal chamber 25. And, conveniently, each module 15, 17, 19 haslevelling feet 27, thereby permitting the modules 15, 17, 19 to bealigned with one another. Referring also to FIG. 4, an auxiliary chamber29, described in more detail below, is between the walls 31, 33.

The thermal chamber 25 is horizontally elongate (at least by virtue oftwo or more modules 15 being attached to one another) and a part of suchchamber 25 is within each module 15 behind (to a viewer of FIG. 3) apanel 35. An air plenum 37 is below the thermal chamber 25 and alongmost of the length of both, the chamber 25 and the plenum 37 areisolated from one another by an imperforate panel 39. But the panellength (measured left-right in FIG. 1) is less than the length of theplenum 37 and chamber 25, thereby providing openings 41, 43 atrespective extreme ends of the plenum 37 and chamber 25. A blower 45,e.g., a centrifugal blower, driven by a motor 46 urges air along anelongate, “race track shaped” path 47 through the plenum 37 and thethermal chamber 25. A heat exchange device is embodied as arefrigeration system 49, the evaporator 51 of which is in the air plenum37. The air being circulated along the plenum 37 and the thermal chamber25 may thereby be cooled for stress test purposes.

From the foregoing, it is apparent that the first section 11 isconfigured for use only in depressed-temperature (i.e., depressed fromambient temperature) stress testing. The second section 13 is configuredfor use only in elevated-temperature stress testing.

The second section 13 differs from the first in that a heating system 53rather than a refrigeration evaporator 51 is in the air plenum 37. In aspecific embodiment, the system 53 includes electrical resistanceheaters.

Referring also to FIGS. 5, 6 and 7, the general interior arrangement ofthe apparatus 10 includes a flat, vertically-oriented carrier 57 onwhich a product 59 to be tested is mounted. The carrier 57 is suspendedfrom a platform 61 which is urged along the auxiliary chamber 29 by aconveyor 65 and flexible partitions 67 isolate the auxiliary chamber 29and the thermal chamber 25 from one another. These features will now bedescribed in more detail.

The new test apparatus 10 has an enclosure 69, within which is theauxiliary chamber 29, the thermal chamber 25 and the air plenum 37. Theauxiliary chamber 29 is bounded in part by first walls 31, 33, 71 whichare substantially free of insulation and the thermal chamber 25 isbounded in part by second walls 73, 75, 77, each comprised insignificant part of an insulation layer 79. In a specific embodiment,the thickness of each layer 79 is over one-half of the total thicknessof a wall 73, 75, 77.

Referring also to FIG. 8, opposed barrier walls 81, 83 extend from therear and front, respectively, of the apparatus 10 and each wall 81, 83terminates in a mounting piece 85. The pieces 85 are spaced slightlyfrom one another and serve to positionally hold a flexible primarypartition 67 a, the purpose of which is described below. Such primarypartition 67 a is comprised of first and second partition members 87,89, respectively, and a preferred partition member 87, 89 includes abrush 91 affixed to an extruded aluminum strip 93 and having flexiblebristles 95 which are carbon-bearing bristles for reducing staticelectricity. Appropriate partition members 87, 89 are available fromSealeze Corporation, Richmond, Va.

A highly preferred apparatus 10 has plural partitions 67, the firstauxiliary partition 67 b also being comprised of a separate set ofmembers 87, 89, and the second auxiliary partition 67 c further beingcomprised of yet another separate set of members 87, 89. The partitions67 b, 67 c are spaced from one another and as is apparent from FIGS. 4and 6, are interposed between the primary partition 67 a and theauxiliary chamber 29. As shown in FIGS. 6 and 7, the brushes 91 of themembers 87, 89 are angled with respect to one another and to the carriercard 107 and each such brush 91 defines an acute angle A1 with thecarrier 57. Such angled orientation is preferred since, when there is nocarrier card 107 between the members 87, 89, such members straightensomewhat and enmesh to form a seal through which air does not easilypass.

A support platform 61 has standoffs 97 mounted atop it for securing atest bed 99 having exposed electrical contact points. An exemplarysupport platform 61 is a square or rectangular slab about one-half inchthick (about 1.27 cm.) and made of DELRIN™ plastic or the like.

Instrument-type test boards such as a load board 101 or a computer board103 may be mounted on the test bed 99. A load board 101 applies a loadto the product 59 under test to simulate the load or aspects of the loadthe product 59 will experience in actual application. A computer board103 periodically “interrogates” the product 59 under test and stores theinformation for later retrieval and analysis. Points on the test bed 99and points on the carrier 57 are in electrical contact with one anotherusing edge connectors 105 or other known means.

And it may be desirable to “exercise” a product 59 undergoing stresstest by carrying out an operating regimen substantially like that theproduct 59 will experience in an actual application. To that end, anembodiment of the apparatus 10 shown in FIG. 13 includes a probe 106.The probe 106 is configured to be lowered and raised to electricallyconnect with the load board 101, board computer 103, the test bed 99 orsome other “interface” board supported by the platform 61 and connectedto the product 59. The probe 106 is further described below.

A preferred carrier 57 includes what is known as a “feedthrough card107.” A typical card 107 is thin, generally flat, rectangular and has asubstantial number of electrical conductors laminated between twoinsulating layers bonded together. Each of the conductors is “broughtout,” i.e., exposed at opposite card ends, for making electricalconnections thereto. Attached to the carrier 57 is a fixture 109 forreleasably mounting an electronic product 59, e.g., a printed circuitboard, on the carrier 57.

The carrier 57 is coupled to the support platform 61 and extendsdownwardly through the partitions 67 a, 67 b, 67 c. The partitionmembers 87, 89 of each partition 67 a, 67 b, 67 c bear againstrespective surfaces 111, 113 of the card 107. As is now apparent, thepartitions 67 a, 67 b, 67 c coact to prevent significant air transferbetween the chambers 25, 29.

It is particularly desirable to prevent warmer, more humid air in theauxiliary chamber 29 from migrating or transferring to the thermalchamber 25 since such transfer speeds the rate at which frostaccumulates in the thermal chamber 25. To the end of further inhibitingtransfer of humid air to the thermal chamber 25, the primary and firstauxiliary partitions 67 a, 67 b, respectively, define a flow path 115between them. Dry air is caused to flow along the flow path 115, therebysubstantially preventing moisture from migrating from the auxiliarychamber 29 to the thermal chamber 25. Good results are obtained byflowing dry air along either one of the flow paths 115, 117 or alongboth.

Referring next to FIGS. 4, 6 and 9, the conveyor 65 has two spaced-apartsections 119, 121, each such section 119, 121 comprising an endless belt123 supported by rollers 125 and driven by one roller 125. Thespaced-apart edges 127 of the platform 61 rest on respective conveyingsections 119, 121. (For clarity, FIG. 6 shows the platform edges 127spaced slightly above respective conveying sections 119, 121.)

Referring now to FIGS. 4, 5, 6 and 10, it is also highly desirable to beable to electrically operate the products 59 under stress test as theymove along through the apparatus 10. Thus, the auxiliary chamber 29contains a power bus embodied as two parallel, spaced-apart rails 129.The support platform 61 includes collector shoes 131 inelectrically-conductive relationship to the power bus rails 129, therebyproviding power to products 59 mounted on the carrier 57.

It is highly preferred that electrical continuity between the rails 129,and the support platform 61 and board 101 or 103 mounted thereon bemaintained. To that end, the support platform 61 includes a first set ofshoes comprising shoes 131 a, which are electrically connected inparallel. Similarly, there is a second set of shoes comprising shoes 131b, which are electrically connected in parallel.

In a specific embodiment, each shoe 131 pivots about an axis 135 and isurged toward its respective rail 129 by springs 137. When the platform61 is so configured, a temporary “bounce” of less than all of the shoes131 a or 131 b away from the respective rail 129 will not interrupt thecontinuity of power to the platform 61.

Referring to FIGS. 1, 2, 4, 11 and 12, the apparatus 10 has at least onemodule 17 with a door 21 mounted for movement between an open positionfor placing products 59 in the thermal chamber 25 and a closed positionfor stress testing the products 59. Door movement is by pneumaticcylinders 139. When the door 21 is closed, it is sealed by anair-inflated seal of a known type. And frost formation on the doors 21is inhibited by a door heater.

FIGS. 11 and 12 show a single door entry module 17 for purposes ofexplanation. And the door 21 is broken away to show the interior of themodule 17 which is also equipped with conveyor sections 119, 121, busbars 129 and the like. After appreciating the specification, an exitmodule 19 and a double door module as shown in FIG. 1 may readily beconstructed.

In a highly preferred embodiment, the modules 15, 17, 19 are made usingfiberglass sheets 141 for the outer surfaces and aluminum sheets for theinner surfaces 143. Aluminum structural extrusions 145 available from80/20, Inc. of Columbia City, Ind. are very useful for joining sheets141, 143 at corners and at sheet edges.

Referring to FIG. 13, the probe 106 includes a stiffening plate 149having electrical boards 151 mounted thereon. Spring-loaded pins 153(sometimes referred to as “pogo pins”) extend through the plate 149 andthe boards 151. (The boards 151 and pins 153 are sometimes referred toin the industry as a “bed of nails.”)

When the probe 106 is lowered, the pins 153 contact respective points onthe bed 99. Guide rods 155 extend through the plate 149 and the plate149 and the boards 151 move upwardly and downwardly under the control ofa pneumatic cylinder 157. It is to be appreciated that the probe 106 maybe mounted for vertical movement only rather than for both verticalmovement (i.e., up/down in FIG. 13) and horizontal movement (i.e.,left/right in FIGS. 1, 2 and 3). But given the specification, persons ofordinary skill will readily appreciate how to configure the probe 106 tomove horizontally along the auxiliary chamber 29.

As used herein, the phrase “dry air” means air, the relative humidity ofwhich is in the range of 5-10% or less. As used herein, the term“thermal chamber” means a chamber, the interior of which exhibits wideexcursions of temperature, e.g., temperature “swings” of +125° C. to+23° C. (about +255° F. to +73° F.), +23° C. to −65° C. (about +73° F.to −85° F.), or even +125° C. to −65° C. (about +255° F. to −85° F.)during stress testing. The term “stress testing” means testingelectrical products using one or more wide temperature excursions.

While the principles of the invention have been shown and described inconnection with a few preferred embodiments, it is to be understoodclearly that such embodiments are by way of example and are notlimiting. As other examples, the new apparatus 10 may be configured toprovide “hot only” stress testing, i.e., stressing testing involvingtemperatures above room ambient. In that instance, the module 15terminating the section 13 may not require a door 21. A hot air“curtain,” or “knife” as it is sometimes called, is adequate.

And cold stress testing may be carried out using a refrigeration unitseparate from and ducted to the apparatus 10. Such unit preferably hastwo redundant evaporators 51 so that one evaporator 51 may be disabledand defrosted while the other evaporator 51 is cooling air flowingthrough the thermal chamber 25.

What is claimed:
 1. A product carrier for supporting an electricalproduct during testing of the product in an environmental test chamber,the environmental test chamber having a thermal chamber and an auxiliarychamber, comprising: a platform positioned within the auxiliary chamber,the auxiliary chamber being normally at room ambient temperature andhumidity; a conveyor for supporting the platform in the auxiliarychamber, the conveyor transporting the platform along a predeterminedpath; an interface board mounted on a surface of the platform; afeedthrough card extending from the platform into the thermal chamberand operatively connected to the interface board and to the electricalproduct, the feedthrough card carrying the electrical product duringtesting; and a rail positioned within the auxiliary chamber andelectrically connected to the interface board for providing electricalpower to the interface board during travel of the platform along thepredetermined path.
 2. The product carrier of claim 1 wherein theinterface board includes a load board for providing a load onto theelectrical product.
 3. The product carrier of claim 1 wherein theinterface board includes a computer board for interrogating theelectrical product and storing information received therefrom.
 4. Aproduct carrier for supporting an electrical product during testing ofthe product in an environmental test chamber, the environmental testchamber having a thermal chamber and an auxiliary chamber kept nominallyat room ambient temperature and humidity, comprising: a platformpositioned within the auxiliary chamber, the platform including firstand second opposite surfaces; an interface board mounted to the firstsurface; a feedthrough card extending from the platform into the thermalchamber for carrying the electrical product during testing, thefeedthrough card electrically connecting the electrical product to theinterface board; a conveyor for supporting the platform within theauxiliary chamber, the conveyor tranporting the platform along apredetermined path thereby transporting the electrical product along ananalogous path within the thermal chamber; and an electrical buselectrically connected to the interface board for providing electricalpower to the interface board during travel of the platform along thepredetermined path.
 5. The product carrier of claim 4 wherein theinterface board includes a load board for providing a load onto theelectrical product.
 6. The product carrier of claim 4 wherein theinterface board includes a computer board for interrogating theelectrical product and storing information received therefrom.
 7. Theproduct carrier of claim 4 further comprising a plurality of stand-offsfor mounting the interface board to the platform.
 8. A product carrierfor supporting an electrical product during testing of the electricalproduct in an environmental test chamber, the environmental test chamberhaving a thermal chamber and an auxiliary chamber between which apartition is interposed, comprising: a platform having an interfacesupport surface, the platform and interface support surface positionedoutside the thermal chamber; an interface board mounted on the interfacesupport surface; a feedthrough card depending from the platform andpassing through the partition, the feedthrough card operativelyconnected to the interface board such that the electrical product iselectrically connectable to the interface board therethrough; and aconveyor for supporting the platform, the conveyor transporting theplatform along a predetermined path within the auxiliary chamber therebytransporting the electrical product along an analogous path within thethermal chamber.
 9. The product carrier of claim 8 wherein thefeedthrough card includes an electrical connector for connecting theelectrical product to feedthrough card.
 10. The product carrier of claim8 wherein the interface board includes a load board for providing a loadonto the product.
 11. The product carrier of claim 8 wherein theinterface board includes a computer board for interrogating theelectrical product and storing information received therefrom.
 12. Theproduct carrier of claim 8 further comprising a rail electricallyconnected to the interface board for providing electrical power to theinterface board during travel of the platform along the predeterminedpath.
 13. The product carrier of claim 8 further comprising a pluralityof stand-offs for mounting the interface board to the platform.